I accidentally filled my 1965 Aston Martin with E15 (15% Ethanol) pump gas. I drove 20 miles before the engine sputtered and died. The ethanol dissolved the original fuel lines, gummed up the carburetors, and caused a lean condition that scorched a piston. Repair bill: $12,000. My insurer said, “You put the fuel in. That’s not an accident. That’s maintenance error.”
Key Takeaways
- “Misfueling” is a Grey Area: Some insurers treat it as an accident (covered); others treat it as mechanical breakdown (excluded).
- Sudden vs. Gradual: If the damage happened immediately (seized engine), you have a better case. If the ethanol ate the rubber seals over 6 months, that is “wear and tear.”
- Pollutants Exclusion: Fuel is a pollutant. Some policies exclude damage caused by pollutants unless it escaped from the tank.
- Vandalism Argument: If someone else put the wrong fuel in, it is Vandalism (Covered). If you did it, it’s harder.
The “Why” (The Trap): The Mechanical Breakdown Exclusion
Policy reads: “We do not cover mechanical or electrical breakdown, failure, or breakage.”
The insurer argues that putting the wrong fluid in caused a mechanical failure. It wasn’t a crash, fire, or theft.
However, you must argue it was an “Accidental Direct Physical Loss”—similar to driving into a lake. You didn’t intend to destroy the engine.
[IMAGE: Photo of a fuel pump handle with a warning “E15 – Up to 15% Ethanol” sticker]
The Investigation: I Called Them
I asked, “If I put diesel in my gas car, or E15 in my classic, do you pay?”
1. Leland West
- Response: They are aware of the issue.
- Stance: They tend to view accidental misfueling as a covered peril under comprehensive coverage, provided it was a specific, one-time error.
2. Standard Carrier
- Response: Denial. “Wrong fuel is operator error/mechanical failure.”
3. UK Insurers (Comparison)
- Note: In the UK, “Misfueling Insurance” is a common add-on. In the US, it is rare. You have to fight for it under the “All Risk” clause.
Comparison Table
| Scenario | Coverage Argument | Likelihood of Payout |
| Ethanol rot over 1 year | Wear & Tear / Maintenance | 0% |
| Accidental Diesel Fill (Sudden) | Accidental Damage | 50-70% |
| Vandal (Sugar in tank) | Vandalism | 100% |
Step-by-Step Action Plan
- Do Not Say “Wear and Tear”: When reporting, say: “I accidentally introduced a foreign substance into the fuel system on [Date], causing immediate failure.”
- Save the Receipt: Prove you bought the wrong gas at that specific time.
- Get a Mechanic’s Statement: Have the mechanic write: “Damage consistent with acute fuel contamination, not long-term deterioration.”
- Check “Misfueling” Endorsement: Ask your agent if they have a rider for this. It’s cheap if available.
FAQ Section
Is E10 gas covered?
No. E10 is standard pump gas. If your car can’t handle it, that is considered an “Inherent Vice” of the antique design. You are expected to upgrade the lines.
What if I use lead additive and it ruins the engine?
Excluded. That is improper maintenance/additive use.
Does this apply to putting DEF in the fuel tank?
Yes, same logic. It is accidental damage. Fight the “mechanical breakdown” denial.